The kinesin superfamily contains a conserved class of microtubule-dependent molecular motor proteins that possess an adenosine triphosphatase activity and motion characteristics. The active movement of kinesins supports several cellular functions, including mitosis, meiosis, and the transport of macromolecules. Mitosis is a process of eukaryotic cell division that involves the division of nuclei, cytoplasm, organelles, and the cell membrane into 2 daughter cells with roughly equivalent portions of these cellular components. Any errors in this process could result in cell death, abnormality (such as gene deletion, chromosome translocation, or duplication), and cancer. Because mitosis is complex and highly regulated, alteration of kinesin expression or function could lead to carcinogenesis. Moreover, because human cancer is a gene-related disease involving abnormal cell growth, targeting kinesins may create a novel strategy for the control of human cancer. Indeed, several such drugs are being tested successfully in the clinic. In this review, the authors discuss in detail the structure and function of kinesins, the correlation of kinesin expression with tumorigenesis and progression, and the development of biomarkers and cancer-targeted therapy involving the kinesin family proteins. Cancer 2010;116:5150-60.